After I got back from the lake the last time I went out, I noticed the back of the trailer wasn't touching the boat anymore.

After further investigation I found both frame rails were rusted out and broken after the axle mount tubing.

I had already repaired a section of the middle cross member here so I knew rust was an issue already. (This repair was done under the boat with a MIG, hence the look)

The boat had spent some time in Florida where I am sure it was exposed to brackish water.

I called around to price a new trailer and got quotes anywhere from $4800 plus shipping to $8500. Lead time was considerable. I thought If I do it myself and reuse alot of the old gear I could save a ton of dough. The torsion axle seemed good, The disc brakes are still good (actuator was shot). Good wheels, just need some new tires. So I decided to dive it and set the boat aside.

To make sure I got all the dimensions the same I am going to build the new trailer on top of the old one, then cut the old trailer out from underneath it. I also made 4 templates out of OSB to replicate the stringer hanger locations and the cross member locations.
The most difficult part so far has been the main side rails. They are press bent 2x4 .120", I dont have access to a bender that will handle that so I need to pie cut the outside of the tubing and weld it back together.
I am a much better on the TIG than the MIG even though it takes longer, a prefer the process.

Borrowing Chunter's Prop guard method
Cutting tail light holes

I have a bunch of goodies on order. I'll post more pics soon. Trying to decide on paint color. Match the boat or gloss black?

I like your way of getting the main frame rails bent. It should actually look pretty cool when it is all ground down and cleaned up. Unlike the frame rails that are bent on a tube bender, yours' won't have the crease on the inside of the bends. Cool stuff!